Apparatus for filtration under pressure



(N0 Model.) 4 Sheets-Sheet 1.

P. R. GRAY, Jr.

APPARATUS FOR FILTRATION UNDER PRESSURE. I No. 596,994. Patented Jan.11,1898.

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P.R. GRAY, Jr. APPARATUS FOR FILTRATION UNDER PRESSURE. No. 596,994.Patented Jan.l1,1898.

WITNESSES: INVENTOR:

$61M, a/dm (No Model.) 4 Shee'tsSheet 3. P. R. GRAY, Jr. APPARATUS FORFILTRATION UNDER PRESSURE.

No. 596,994. I Patented Jamil, 1898.

WITNESSES: 06 P VENT R:

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(No Model.) 4 Sheets-Sheet 4.

P. R. GRAY, Jr. APPARATUS FOR FILTRATION UNDER PRESSURE.

' No. 596,994. Patented Jan. 11,1898.

WITNESSES:

UNITED STATES PATENT @rrrcn.

PIIILANDER R. GRAY, JR., OF ELIZABETH, NEW JERSEY.

APPARATUS FOR FILTRATION UNDER PRESSURE.

SPECIFICATION forming part of Letters Patent No. 596,994, dated January1 1, 1898.

Application filed November 13, 1896. Serial No. 611,947. (No model.)

To oaZZ whom it may concern:

Be it known that I, PHILANDER R. GRAY, J12, a citizen of the UnitedStates, residing at Elizabeth, in the county of Union and State of NewJersey, have invented certain new anduseful Improvements inFilter-Presses, of which the followingis a specification.

My invention comprises certain improve ments in the construction of whatare known as filter-presses such as are used, for instance, for theseparation of oils and animal fats into constituent parts. In treatingmaterials in filter-presses as they have hereto fore been constructedand operated the material is subjected to pressure filtration atsubstantially the same temperature throughout the entire operation. Forinstance, in treatin g animal fats in such presses to separate thestearic acid from the oleic acid at a suitable temperature to cause theexpulsion from the press of the oleic acid and the retention in thepress of the stearic acid the practical limitat-ion as regards theresult is that from ten to twelve per cent. of the oleic acid willremain in the cake of stearic acid retained in the press. As acommercial quality of stearic acid musthave a lower percentage of oleicacid present, it has been necessary to remove the stearic-acid cake fromthe press and treat it by another process to eliminate a part of theremaining oleic acid until the quantity of such acid in the stearic-acidcake is reduced to from one to two per cent. or thereabout. It is notfeasible when proceeding according to the old method to work thematerial at such a high temperature as to eliminate the oleic acid tosuch extent that commercially-pure stearic-acid cake will be retained inthe press, for the reason that when such temperature is employed in thefirst part of the operation a considerable percentage of the stearicacid will be expelled from the press along with the oleic acid. Vhiletherefore the cake remainingin the press would be for commercialpurposes sufficiently low in oleic acid, the product expelled from thepress would not be commercially-pure oleic acid because of the presenceof too high a percen tage of stearic acid. For this reason the mode ofoperation has been that which I have above suggested.

In operating my improved press the material may be worked at theordinary temperature to efiect such proper separation as to eX- pel fromthe press a commercially-pure oleic acid, which is run off into asuitable receiver. The temperature of the press and the containedmaterial may then be raised, continuing the operation, preferablywithout interruption in the usual way, the product expelled from thepress being then oleic acid containing an undesirable percentage ofstearic acid. This product of the press is returned to the material thatis being prepared to be fed to the press, while the percentage of oleicacid ,in the steario-acid cake retained within the press has by theoperation mentioned been reduced so low that the stearic-acid cake iscommercially pure and does not require further treatment. Thus by thefirst part of the run of the press a quantity of commerciallypure oleicacid is expelled, while the cake remainingin the press is notcommercially-pure stearic acid. Then by raising the temperature andcontinuing the operation a product expelled from the press of oleic andstearic acid combined, and this product is chilled and mixed with thematerial that subsequently is fed to the press; but the cake nowretained in the press is commercially-pu re stearic acid and may beremoved from between the plates of the filter-press when the operationhas been carried to the proper point.

To this end my invention comprises an improvement in the construction ofa filter-press, which consists in means whereby the press and itscontents may at a suitable time be heated tothe desired temperature tocifect the operation above stated. My invention also consists in animproved construction of the filter plates and of a trough or receptaclefor receiving products expelled from the press and in certain details ofconstruction, all as hereinafter specifically set forth.

In the accompanying drawings, Figure 1 is face of the rear head of thepress, as indicated by the line 3 3 of Fig. 1, looking in the usual inpresses of this class, the feedingdirection of the arrow. Fig. 4 is adetail View showing one of the separating-rings that are placed betweenthe filter-plates. Fig. 5 is a detail View, partly in section and partlybroken away, of the front or left-hand end of the trough arranged belowthe press. Fig. 6 is a transverse section through the opposite end onthe line 6 6 of Fig. 7, looking in the direction of the arrow. Fig. 7 isa view similar to Fig. 5, but of the opposite end of the trough. Fig. 8is an edge view, partly in section, on the line 8 8 of Fig. 9, lookingin the direction of the arrows, of one of my improved filter-plates.Fig. 9 is an elevation of the face thereof, partly broken away to showthe construction more clearly. Fig. 10 is a view of a segment of one ofmy improved filterplates, partly broken away and partly in section, onthe line 10 10 of Fig. 11. Fig.'11 is a transverse section on the line11 11 of Fig. 10. Fig. 12 is another view of a segment of a platesomewhat different in construction, partly broken away and partly insection, on the line 12 12 of Fig. 13. Fig. 13 is a transverse sectionon the line 13 13 of Fig. 12, and Fig. 14 is a transverse sectionshowing another construction of filter-plate.

A A represent the end frames of the press, having cross-bars B, and 0represents the fixed head of the press, carried by the rear frame A.

C is the sliding or movable head and is mounted and slides upon therods, tie-bars, or rails D, all as usual.

D indicates the ordinary hydraulic cylinder, and D its piston forsetting up the head 0 against the plates and withdrawing it when thenuts on the holding-bolts F are loosened,

all as usual in this class of presses.

F indicates the holding or clamping bolts, extending through the twoheads and provided with clamping-nuts. The construction and arrangementof these parts are as usual, except that the clamping-bolts are formedwith ends f, extending beyond the screwthreadf, on which theclamping-nuts work. These ends are of less diameter than the threadedparts of the rods, the purpose being that when the clamping-n utsf areunscrewed to open the press the nuts can he slipped back on the reducedpartfof the bolts and are prevented from slipping off of the bolts bypins or keys f in the ends thereof, and the movable head when drawn backdoes not become disengaged from the bolts. Heretofore in opening pressesof this character the head when run back passes clear of the ends of thebolts, necessitating some means of support for the bolts, in order thatthey will enter their respective openings in the head when it is againset up. Also,the clam ping-nuts when run back on the bolts have beendisengaged from the bolts, usually being dropped upon the floor, a planthat is both inconvenient and liable to cause the fouling of the nutswith dirt and grit. As is tube opens through the central aperture C inthe fixed head 0 into the bore formed by the central openings in theassemblage of filter-plates, which bore is, however, closed by the solidmovable head 0.

As regards the filter-plates they are of course each provided with theusual lateral lugs, by which they are supported and slide upon thetie-bars or rails D. I have shown in the accompanying drawings severaldifferent styles of filter-plates, all having, however, a commoncharacteristic feature of construction.

In Figs. 8, 9, 10, and 11 I have shown a filterplate constructed asfollows: G indicates an annular ring provided with the ordinary sidelugs g, that support the ring upon the rods D, and with aninternally-projecting annular flange G. The ring G may be of cast-ironand the inwardly-projecting annular flange G may be a wrought-iron ring,around which the cast-iron ring G is cast. Two perforated plates II andI, fitted within the ring G, embrace the fiange G and are bolted theretoby bolts g. The plate 11 may be, as shown, a flat plate with aperturesor perforations 7L punched therein. The plate I is formed withcoincident apertures v; and with laterallyprojecting lugs i, eachextending from an edge of an aperture and against which the fiat plate Hbears. As shown, the apertures and laterally-projecting lugs of theplate I are formed by cutting or punching out the metal to form threesides of an aperture, the tongue or piece of metal left attached to theremaining side of the aperture being forced or turned outwardly at rightangles to the plane of the plate.

In the figures to which I have referred the lugs 1" are all turned inthe same direction. Obviously, however, some might be thrown out on oneside of the plate and some on the other, in which event a flatperforated plate I-I would be placed on each side of the plate I, and inthat case the plate I would fit within the flange G, while the fiat sideplates would embrace this flange and be secured by the bolts 9. Thismodification of the construction shown in figures referred to will beplain when the construction of the plate indicated in Figs. 12 and 18 isdescribed. The cloth enveloping the plate is indicated by K and isapplied in the usual way, leaving a central opening K in the plate, asusual. The exterior edges of the cloth maybe secured at intervals aroundthe periphery of the plate by bolts 70, passing through eyelets in thecloth and through projections formed at intervals on the ring G. Theordinary bun gs or blocks M may be attached to the plates by rivetspassing through the plates, as indicated in Figs. 8 and 9, or may besecured to the cloths only or in any other suitable way, the two waysmentioned being common and well understood. There spacin g-rin gs N areplaced between the plates, the bungs- M pro- IIO ject to such'extentthat those on the adjacent faces of the plates will meet in the centralplane of the spacing-ring, as is the common practice; but wherespacing-rings are not employed the bungs on the plates will not projectbeyond the planes of the faces of the rings G, an arrangement that isalso common.

So far as I am aware the manner described of forming perforated membersof a filterpress plate is new. At the under side or lowest of thesefilter-plates the flange G is cut away, as indicated at G Fig. 9, andthe recess thus formed in the flange G constitutes an opening thatcommunicates with an aperture G extending through the ring and forming adischarge-outlet for the plate through which the expressed product maybe delivered into the trough X, Fig. 1.

In Figs. 12 and 13 I have shown a filterplate difiering in the followingparticulars from the plate thus far describedthat is to say, the plateis composed of a central memher I, fitting within the annular flange Gand having relatively large apertures t, the metal, which is attached atone edge of each aperture, being thrown out, as already described, toform the laterally-projecting lugs 13. In these two figures,however,Ihave embodied the suggestion made in connection with Figs. 10and 11. The lugs t" are thrown out from both faces of the plate and theflat perforated plates H, having apertures h, in this case shown ascircular, embrace the flange G and are securedthereto by theclampingbolts g.

In order to provide means for carrying out the method of operationhereinbefore described-via, to provide a means for raising thetemperature of the press and the contained material at the desired pointin the operationl have shown in the drawings the following construction:The upper edge of each filter-plate ring G is formed with an enlargement0, having therein an aperture 0, which opens by a radial passage 0,through the cast part G of the ring and through the flange G into theinterior of the plate-'i. 6., into the open space between the perforatedplates. The spacing-rings N when employed should be formed with similarenlargements N and apertures n corresponding with and registering withthe apertures 0 in the filter-plate rings. The apertures n or 0 in aspacing-ring or filter-plate ring is, at one end of the press, closed bythe movable head 0 of the press, while the fixed head C is formed withan aperture or passage 0 that communicates with the aperture n or o inthe spacingring or filtenplat-e ring at that end of the press. Thepurpose of this arrangement is, as stated, to afford a means for raisingthe temperature of the press and its contents at the desired time, andfor this purpose I mayintroduce through the opening C hot air or steamof a temperature suitable to effect the desired result, accordingto thematerial that is under treatment.

It is obvious that if hot air or steam be introduced at the aperture 0it will pass along the longitudinal bore formed by the apertures n 0into the interior of the respective plates and out through thedischarge-openings G therein. In the practice of my invention I continuethe ordinary operation of the press until the spaces between thefilter-plates are approximately well filled with the retained materialor cake. I then raise the temperature by the means stated, or any othersuitable means, and continue the operation in the ordinary way. Thus intreating animal fats the ordinary operation is continued until thespaces between the plates are Well filled with stearic-acid cake, acommercial product of oleic acid having been expelled from the press. Ithen either suspend the feeding of the press or during the continuationof such feeding introduce the heating medium, and as the temperatureincreases most of the oleic acid retained in the cake, together with apart of the stearic acid, will be eliminated. The mixed product thus eX-pelled from the press is mixed with the material being prepared for thepress, while a commercially-pure stearic acid is retained in the press.\Vhen the operation is completed, the press is opened in the ordinaryway and the stearic-acid cake discharged. The parts of the press arethen reassembled and a further similar operation started.

I have referred particularly to the treatment of animal fats, as that isa fruitful field of usefulness for my invention; but I do not, however,limit the use of the press to the treatment of such material, asobviously it is applicable for other purposes.

As an illustration of the temperatures that may be employed in the useof my press for producing stearic and oleic acid from animal fat, I maystate that during the first part of the operation the material may beworked at a temperature of about Fahrenheit, and the temperatureincreased for the latter part of the operation to about 180 Fahrenheit.The proper temperatures at which to operate upon any material will ofcourse be apparent to those skilled in the art of working such material.

The construction of the perforated members of the filter-plates which Ihave described is of course applicable to that class of plates in whichthe perforated plates or members are merely bolted to an annular ringlocated between the plates near their edges. In such case thesupporting-lugs 9 may be formed either on the interposed ring or on theperforated members of the plate. Such a plate is indicated in Fig. 14,which shows perforated members II I, such as indicated in Figs. 10 and11, with a ring V bolted between them. K indicates the ordinary cloth.The peculiar construction of the perforated members being new with me, Ido not limit its use to any partic ular style of filter-plates. Thedotted lines K at the bottom indicate how the edges of the cloth arebrought together, except at the point of discharge, where they arepreferably left, as shown by the full lines at this point.

Ihave shownin Figs. 1, 2, 5, 6, and 7 a novel organization relating tothe trough for receiv' ing the products expelled from the press. Thispart of my invention comprises a trough to receive the products expelledfrom the press and from which different grades of such product may, asdesired, be delivered into diflerent receptacles, and which when thecake is to be discharged from the press may be moved to one side out ofthe way and inverted, so as to avoid liability of parts of the cakebeing delivered into the trough, where they might become mixed as animpurity with the expelled product of the press in the next operation.For this purpose I have shownthe following organization: The trough X isc0mposed of a length of pipe of suitable diameter, which is cut awaythroughout its central portion to form an open trough, but is left solidat each end, where it is closed by ascrew cap X. The outlet-pipe X isconnected-with the discharge end of the trough and may receive aflexible pipe to convey the product to any desired receptacle. At thefront end the end of the pipe forming the trough is fitted in a ring P,having a flat base P, which rests upon the cross-bar B of the frontframe, and has a bolt passing through a slot B in this bar and having aclamp-nut P on its end below the bar. Pins 10 in the annular outer sideof the trough embrace the ring P. Byloosening the nut P the end of thetrough may be shifted laterally and it may also be turned over orinverted, the annular end turning in the ring P and being held againstendwise movement by the pins 19. At the opposite end there is a similarring Q, having a similar base Q and bolt and clamp-nut Q the cross-barof the rear frame being also slotted, as at B The ring Q, however, isprovided with two projections R R, extending in the direction of thelength of the trough and adapted to be engaged by a stop-pin q in theside of the pipe. Thus when the trough is turned over or inverted thestop-pin q leaves the projection R and comes against the projection R,and the trough is held in either position by a weight S on the end of anarm 8, secured to the end cap of the trough and projecting laterallytherefrom at right angles. By means of this organization the trough maybe placed under the outlets G3 of the filter-plates to receive theexpelled product, which may be delivered through the pipe X to asuitable receptacle,

and then when the press is to be discharged of the cake in the usual waythe trough may be shifted to one side out of the way, as indicated inFig. 2, and also inverted to prevent any of the product then dischargedfrom entering it. This feature of my invention may be modified in detailof organization, and so far as I am aware it is new to employ in a pressof this character a laterally-movable invertible trough.

I claim as my invention- 1. In a filter-press, the combination of aseries of filter-plates each having an opening to form the bore throughwhich the material being treated is delivered to the compartmentsbetween the plates, and also each having perforated members enveloped infilter-cloth and and an open-work or skeleton member placed looselywithin said flange and between the perforated plates, substantially asset forth.

3. In a filter-plate, the combination of an annular ring or frame havingan inwardlyprojecting flange, perforated plates secured respectively tothe opposite faces of the flange, and an open-work or skeleton memberplaced loosely within said flange and between the perforated plates, thering or frame having a discharge-opening formed in it leading from thespace between the perforated plates, substantially as set forth.

4. In a filter-press, the combination of a series of filter-plates eachcomposed of a ring or frame having an inwardly-projecting flange,perforated plates secured respectively to the opposite faces of theflange, an open-work or skeleton member placed loosely within saidflange and between the perforated plates, and filter-cloth envelopingeach plate, each ring being formed with an outlet leading from theinterior space between the perforated plates, and an aperture in linewith the axis of the plate connected by a passage with said interiorspace of the plate, said apertures being in alinement and forming apassage-way for the introduction of a heating medium to the interiorspaces of the plates, substantially as set forth.

5. In a filter-plate, the combination of two perforated members, one ofwhich is a flat perforated plate and the other of which has the metalcut out to form the perforations attached to an edge of the perforationand turned out laterally to form projecting sup ports for the flatplate.

6. In a filter-plate, the combination of three perforate members whichare respectively a central member having the metal cut away to form theperforations attached to one side of the perforation and turned outlaterally from the plate to form the projecting lugs, some of suchprojections being on one side of the plate and some on the other, and aflat perforated plate applied on each side of the central plate,substantially as and for the purpose set forth. 1

7. In a filter pla'te, the combination of an annular ring or framehaving an interior-lyprojecting flange, a perforated plate fittingwithin such flange and having the metal cut away to form theperforations attached to one edge of the perforations and turnedoutwardly to form laterally-projecting lugs,some of such lugs beingturned out on one side of the plate and some upon the other, two flatperforated plates arranged respectively on opposite sides of the centralplate and embracing at their edges said inwardly-projecting flange towhich they are attached, and the filteringcloth enveloping the plate.

8. The combination, substantially as set forth, of the frames A A, thefixed head 0, a movable head G, the bars D, filter-plates and theclamping-bolts F having clamping-nuts and ends f of reduced diameterextending beyond the threads to receive the nuts when run off of thethreads and to support the ends of the bolts in the movable head.

9. The combination with a filter-press, of a laterally invertiblereceiving trough provided with a stop and Weight by which it is held ineither position as regards its inversion.

10. The combination, substantially as set forth, of the end frameshaving the slotted cross-bars, the trough having annular ends, and ringsembracing the annular ends and having bases resting upon the cross-barsand clamping-bolts extending through the slots therein.

11. The combination, substantially as set forth, of the end frameshaving cross-bars, the trough having annular ends, a ring at one end ofthe trough embracing the annular end thereof and movable laterally uponthe crossbar, a similar ring at the opposite end of the trough embracingits annular end and having stops R B, and a stop-pin on the annular endof the trough.

In testimony whereof I have hereunto subscribed my name.

PHILANDER R. GRAY, JR.

\Vitnesses:

EDVVABD O. DAVIDSON, CHARLES L. MALCOLM.

